English UsageComparison guide
Willful vs. Wilful
“Willful” and “wilful” are regional spelling variants of the same adjective. Cambridge identifies “willful” as the US spelling of “wilful.”
Use “willful” in US English and “wilful” in UK-oriented English, unless your house style specifies otherwise.
Key details
Confusion Familyregional spelling
Rule Familyregional-orthography
TermsWillful, Wilful
Variant ScopeCambridge identifies “willful” as the US spelling of “wilful.”
Further guidance
Core difference
“Willful” and “wilful” are regional spellings of the same adjective.
Usage Boundary
Use “willful” in US English and “wilful” in UK-oriented English unless a house style requires another convention.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Willful — Cambridge Dictionary (opens in a new tab)Cambridge University Press · Direct evidence identifying willful as the US spelling of wilful.